Automatic traffic signal



Nov. 6, 1923.

c. M. SNELL AUTOMATI C TRAFFI C S IGNAL Filed May 25, 1923 2 Sheets-Sheet l INVENTOR.

LZm 7%. W BYM ATTORNEYS.

Nov. 6 1923.

C. M.,SNELL AUTOMATIC TRAFFIC SIGNAL Filed May 23, 1925 2 Sheets-Sheet 2 I N V EN TOR.

BY g

A TTORNEYS.

Patented Nov. 6, 1923.

CHARLES M. SNELL, O F DANBURY, CONNECTICUT.

- AUTOMATIC 'rnnrrro SIGNAL.

Application filed May 23,

7 '0 all whom it may concern:

a citizen of the United States, residing at Danbury, county of Fairfield, State of onnecticut, have invented a new and useful Automatic Traffic Signal, of which the following is a specification. I

This invention relates to traffic signals adapted to be placed at street intersectionsto control the traflic in both directions, and has for an object to provide a device of this character which will be operated automatically and at predetermined intervals to show a Stop signal for the traffic in one direction and a Go signal for the traflic in the other direction.

It is also an object of the invention to provide an audible signal which will be sounded by the device a suitable length of time before the visible signals are operated.

It is a further object of the invention to provide an improved mechanism for operating the signals, one that will be simple in construction and reliable in operation so that it will not be easily gotten out of order, and which may be operated at co-mpara-- tively low cost.

With the foregoing and other objects in View, I have devised the contruction illustrated in the accompanying drawings, in which Fig. 1 is a side elevation of a device showing the protecting casing in section.

Fig. 2 is a similar view looking from the right of Fig. 1 with the casingremoved and a portion of the mechanism broken away to more clearly show the construction, and

Fig. 3 is a detailed section substantially on line 3-3 of Fig. 2. Y

The device illustrated is of the four arm semaphore type traffic signal two of which have the Stop-Stop signs and'the other two the Go-Go signs, and these four arms are automatically rotated a quarter revolution at predetermined intervals by improved mechanism for controlling the traffic, the device being designed to be placedat the center of streetintersections as is usual .in such devices.

Referring to the drawings, a suitable supporting frame 5 is provided preferably of structural steel on which the signal arms and the operating mechanism therefor is mounted. For this purpose a standard 6 is mounted on the frame 5 having a cylin- 1923. Serial No. 640,867

drical portion 7 at its upper end on which the signal arms 8 and 9 are mounted to rotate,'two'of these arms, as 8 being provided with the Stop-Stop signals 10 and the other arms 9 with the Go-Go signals 11. I have also preferably provided a dome 12 above these arms in which is mounted a suitable electric light.

The signalarmsare connected to a block 13 embracing the cylindrical portions 7 of the standard and carrying at its lower end a beveled gear 14. This block is mounted to rotate on the standard through suitable ball or roller bearings 15 and 16. The bevel gear 14 meshes with another bevel gear 17 carried on transverse shaft 18 mounted in suitable bearings in the standard, and loosely mountshaft 18 so as to rotate therewith is a toothed ratchet wheel 25, the teeth of which are adapted to be engaged by the pawl 20. Thus this ratchet and through it the shaft 18 will be rotated by the pulley 19 when this pulley is rotated under the action of the weight. 24. To limit the rotation of this pulley under the action of the weight and to thus properly position the signal arms 8 and 9, a suitable stop mechanism is provided. For this purpose Ipreferably provide a stop 26 on the standard and a lug 27 carried by the pulley 19 to engage this stop to limit the movement of the pulley. Also carried by the pulley 19 is a gear segment 28 adapted to mesh with a gear segment 29 carried by a worm gear 30 mounted on a suitable shaft 31 having suitable bearings in the standard. The worm gear 30 meshes with a worm 32 mounted on a shaft 33 which carries a worm gear 34 meshing with a second worm 35 on a shaft 36" to which the rotating element of an electric motor 37 is connected. This electric motor is intended to operate continuously and through the gear 35-3432 to rotate the gear 30- continuously and with it the gear segment 29. The segments 28 and 29 are so located that upon each rotation of gear 30 the segment 29 carried thereby will engage segment 28 and rotate it and pulley 19, counterclockwise as viewed in Fig. 2, one quarter revolution raising the weight 24; without rotating shaft 18. On a continued rotation of the gear 30 segment 29 will pass from engagement with segment 28 and then pulley 19 will be rotated to the right, or clockwise, as viewed in Fig. 2, one quarter revolution by the weight 24-. During this last quarter rotation, however, the pawl 20 will engage a tooth of ratchet wheel 25 and through the shaft 18 and bevel gears 17 and let will rotate the arms 8 and 9 a quarter revolution thus changing the traffic signals for the intersecting lines of trailic. he intervals between the operations of these signals will, of course, depend upon the speed of the motor and the ratios of the driving gears between this motor and the gear 30. Of course if desired a suitable spring may be used instead of the weight, but I prefer the weight.

To avoid confusion by giving an audible warning signal a short time before the semaphore or visible signals are changed, I provide another signal which in the present instance is a whistle 38 although it may be a hell or other device suitable for sounding a signal. This is automatically sounded by the continuously running motor a short time before the semaphore arms are operated, and for this purpose I mount on the shaft 31 a suitable trip mechanism 39 adapted to engage an operating lever 40 for the whistle which is automatically closed by a suitable spring 41. Air for operating the whistle is furnished by a suitable pump or blower 42 operated from a motor shaft by a suitable belt 48 and pulleys 44-45.

For use at night the Stop-Stop and Go-Go signals may be illuminated by suitable lamps 46, and these lamps are connected with suitable electrical connections 47 extending through the arms 8 and 9. As these arms rotate suitable contacts are provided for leading the current from the stationary support to these lamps. For this purpose I have shown insulated rings &'8 carried by the block 13 to which the electrical connections 47 are attached, and connected with insulated elements 49 carried by the standard are brushes 50 contacting respectively with the rings 48, and these brushes have electrical connection with conductors 51 leading to a suitable source of supply. If desired, leads 52 may also be connected with these brushes and extend to the lamp in dome 12.

For the purpose of protecting this mechanism and the bearings there is mounted on the standard above these contacts an inverted bell ordome 53 which extends down about the elements to protect them. The operating mechanism for the arms is preferably enclosed by a suitable casing 54: which may be provided with doors or be made in sections to give easy access to the mechanism for inspection and repair.

It will be apparent from the foregoing description that the operating mechanism for the signal arms is very simple in construction and will be very reliable in operation as it is not likely to be easily gotten out of order. It also may be operated at comparatively low cost. As the motor is continuously operated and operates through the reducing mechanism a motor of great power will not be required. With this mechanism disclosed the signal arms will each time be operated exactly quarter revolution, and so on each operation will be brought to the exact position desired and will be retained therein until the next operation.

Having thus set forth the nature of my invention, what I claim is:

1. In a device of the character described, a signal device, a rotatable element, a. one way driving connection between said element and said device, means arranged to rotate said element in one direction and through said one way driving connection to operate said device, a stop to limit the said operation, a gear segment "arried by said element, a second rotating element carrying a gear segment adapted to mesh with the first segment to rotate said first element in the opposite direction to store energy in said means, and a motor for rotating said second element.

2. In a device of the character described, 100 a rotatable signal device, a weight, a one way driving connection from said weight to said signal device, a continuously operating motor, and means operated by the motor for intermittently lifting said weight.

3. In a device of the character described, a rotatable signal device, av rotatable element, a driving connection from said element to said device arranged to rotate said device when the element is operated in one direction 119 only, a weight for operating said element in the latter direction, a continuously operating motor, and means operated by the motor for intermittently operating the element in the opposite directionto lift said weight.

st. In a device of the character described, a rotatable signal device, a rotatable element, a. pawl and ratchet driving connection be tween said element and said device, a weight arranged to rotate said element in one 120 direction and through said pawl and ratchet to operate said device, a stop to limit the said operation, a continuously operating motor, and means operated by said motor to intermittently rotate said element in the 125 opposite direction to lift said weight.,

5. In a device of the character described,

a rotatable signal device, a rotatable element, a pawl and ratchetdriving connection between said element and said device, a 130 weight arranged to rotate said element in one direction and through said pawl and ratchet to operate said device, a stop to limit the said operation, a gear segment carried by said element, a second rotating element carrying a gear segment adapted to mesh With the first segment to rotate. said first mentioned element in the opposite direction, and a motor for rotating said second element.

10 6. In a device of the character described,

a visible signal, a power means, means connecting said power means and signal for intermittently operating said signal, a con tinuously operating power means for storing energy in said'firs't mentioned power means, an audible signal, and means operated by the second mentioned power means for operating the latter signal.

In testimony whereof I afiix my signature.

CHARLES M. SNELL. 

